A US woman who shot and killed her husband and two adult children before taking her own life is thought to have committed the shocking crime as a result of being ostracised from the religion she was raised in.

Every time I tell a mate I’m doing a story on cryptocurrency, they invariably ask me the same two questions: should they invest their own hard-earned money, and which cryptocurrency will get them a Lamborghini/yacht/island quickest?

Labor's tax plan may hit growth: BCA

Big business is concerned that federal Labor's plan to close multinational tax loopholes will slow economic growth.

In what shadow treasurer Chris Bowen described as an "opening salvo in the battle of ideas", Labor's first major policy announcement in opposition is to introduce a range of measures to stop billions of dollars of tax bleeding offshore.

The tax package, that has been costed by the independent Parliamentary Budget Office, is worth $1.9 billion over four years in additional revenue.

It includes tightening of the so-called "thin capitalisation" rules which allow companies to offset profits against debt servicing costs in high tax jurisdictions such as Australia to reduce their taxable income.

"How much tax you pay shouldn't depend upon how much you can afford to pay your tax lawyer and specialist accountants," Opposition Leader Bill Shorten said at the official policy launch.